Method and apparatus for use in taking impressions of edentulous mouths



Jin-me l0, 1930. c. B. DENNIS 1,763,553

l METHOD OF AND APPARATUS FOR USE` IN TAKING.

IMPRESSIONS OF EDENTULOUS MOUTHS Filed March2l, 1929 2 Sheets-Sheet l lgwuentoz e 72 n a June 10, 1930.

C. B. DENNIS METHOD 0F AND APPARATUS FOR USE IN TAKING IMPRESSIONS 0FEDENTULOUS MOUTHS Filed March 21. 1929 2 Sheets-Sheet 2 gwuentcfPatented June 1Q, 193() UITED STATES PATENT Norifice CHARLES B. DENNIS,OF CONNEAT LAKE, PENNSYLVANIA i METHOD AND APPARATUS FOR USE IN TAKINGIMPRESSIONS OF 'EDENTULOUS MOUTHS Application filed March 21, 19219.Serial No. 348,900.

This invention relates to method of and apparatus for use in takingimpressions of cdentulous mouths. j

In the ordinary process of making such impressions as at presentpracticed, a modeling compound is placed in a tray l and While inposition'in the tray is subjected to pressure to cause the modelingcompound to conform to the contours of the mouth. It is then removed andthe impression covered With a thin batter of plaster of Paris, afterWhich it is replaced in the mouth, pressure applied thereto and theplaster of Paris allowed to harden. This process is open to objection inthat the heated compound compresses and displaces the thin layer oftissue or mucosa covering the maxillal. Use of the plaster layer failsto eliminate this objection and furthermore, the impression is in suchclose Contact to the tissue that very little space is left for theplaster, making it extremely dicult to separate and producing a roughmodel.

Accordingly, an important object of the present invention is to providea method of forming such impressions wherein compression anddisplacement of tissue during the linal step of formation of theimpression is avoided.. and wherein it is possible to construct theimpression with the use of a minimuni amount of plaster, thus lesseningthe discomfort to the patient.

Mv method and apparatus are illustrated in the accompanying drawings,wherein Figure l is a plan view of an impression of an edentulous mouth;

Figure 2 is a section on line Q-Q of Figure l, illustrating the firststep in the process of forming an impression;

Figure 3 is asimilar view showing the next sten therein;

Figure 4 is a similar view shoiviugthe third step;

Figure 5 is a sectional. view through the complete impression;

Figure 6 is a plan View of the accessory emploved in carrying out myprocess;

Fieure 7 is a section on line ure 6.

In accordance With my invention, I first form the compound impression inthe usual manner. After formation of the compound impression C, I placethereon a filler consisting of tivo sheets of Wax 10 and ll cut toconform substantially to the modeling compound and having arrangedtherebetween a separating medium consisting of some thin, flexiblematerial, such as a very fine sheet of rubber, indicated at l2. rlhisfiller is heated and pressed into the compound impressionso that itsubstantially conforms to the shape there of. The compound impressionwith the filler is then placed in the p at-ients mouth and pressureapplied. When removed from the mouth, a Wax impression is provided forwhich the compound impression acts as a tray. Y

The next step in the process is the removal of the upper Wax sheet 11and the separat-ing medium 12, this separation being facilitated by the.use of the separating medium which prevents the sheets of the fillerfrom adhering to each other.

Removal of the upper Wax layer or sheet leaves a space of predeterminedthickness in the impression over the entire area thereof which may befilled With plaster of Paris be fore th-e impression is again placed inthe mouth. Since the space provided is uniform, the thickness ofthe caseprovided will be uniform and a smooth, finished impression in theplaster can be obtained.

It will be obvious that by employing this method, failures in theformation of impressions may be reduced to a minimum and the Work of thedentist accordingly facili tated and decreased. The Wax sheets l() andll with their separating media l2 may be sold as a unit in dilferentsizes and shapes as are the ordinary dental trays, j

i lhile I have above consistently referred. to the use of a compound informino? the original or rough impression, it will, of course, be understood that instead of the compound, I can employ Wax or any othersuitable substance having the desired `characteristics and I am stillassured of having a thin uniform layer of plaster in completing theimpression.

While I have above referred to the use of Wax sheet-s, it will, ofcourse, be obvious that in the use of this term, I refer not only to ysheets of actual wax but likewise to sheets of composition materialhaving the same or similar properties. I claim l. The method of takingimpressions of edentulous mouths consisting in forming the usualcomposition impression, superimposing upon this impression a pair oflayers o f plastic material having a medium arranged therebetween tofacili-tate 'separation thereof, reforming the impression in the layers,removing the outer layer and substituting therefor a substance in asemi-liquid state which hardens as it dries and forming an im- Ypression in said substance.

2. As Van article of manufacture, a filler forv `a compositionimpression comprising upper and lower layers of lplastic material and amedium between the layers to prevent vthem from adhering to each otherso as to'permit the removal of the upper layer after an im` pression hasbeen made in the filler.

3. The method of taking impressions of edentulous mouths consisting informing an approximate impression, superimposing -upon the approximateimpression a plastic materlal, reforming the impression 1n saidmaterial, removing the upper portion of said material, and `substitutingfor :the removed `por- Y f tion of said material a. substance hardenedasit dries and forming'an impression insaid substance. l

4. The method Vof taking impressions of edentulous mouths consisting informing van approximate impression, superimposing upon the approximateimpression a pair of layers of plastic material` of uniform thicknesshaving a mediumarranged therebetween to facilitate separation thereof,reforming the impression .in the layers, removing lthe outer layer ,andsubstituting therefor' a substance hardening as it dries amdforming animpression in said substance.

5. The methodxof taking impressions .of

ledentulous mouths consisting in forming :an

approximate impression, superimposing upon the approximate impressionapaar ofv layers of wax of uniform thickness having arranged therebetweena thin, flexible sheet of rubber, reforming the impression in the1ayers, removing the louter layer, superimposing the .casting-materialupon ztheimder layer and forming an impression in 4the casting material.i

6. A dental impression o f an edentulous mouth comprising'a compositionbase lfor-med to approximate the-impressie@ a layer of wax of uniform:thickness superimposed upon the Y composition and likewiseapproximating-the impression, anda ,uniform plaster .layer upon.

the wafx layer and providing the .exact pression. p.

In .testimony whereof 1I hereunto. afx my signature. v

' Y .CHARLES B. DENNIS.

